2 Corinthians

In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,

And the Lord said unto him, Go through the midst of the city, through the midst of Jerusalem, and set a mark upon the foreheads of the men that sigh and that cry for all the abominations that be done in the midst thereof.

The Spirit itself beareth witness with our spirit, that we are the children of God:

Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.

And hope maketh not ashamed; because the love of God is shed abroad in our hearts by the Holy Ghost which is given unto us.